The objectives of this project are to determine and characterize the highest level of genetic regulation which is altered consistently during malignant transformation, to compare the state of genetic control in tumors with that of immature tissues, to correlate these results with other characteristics of tumors in order to explain the molecular genetic mechanisms of carcinogenesis and tumor progression. The pattern of altered gene regulation in radiation-induced tumors will be determined and compared with the patterns of chemical and viral tumors which have already been characterized. The molecular genetic basis for hormone dependency and temperature sensitivity of tumors will be studied. The fate of the RNA which is released to the cytoplasm abnormally during carcinogen treatment will be determined. The relationship will be defined between loss of transcription of repetitive DNA, loss of transcription of nonrepetitive DNA, and other indications of tumor progression such as increase in growth rate, ability to metastasize, and loss of hormone dependence. Various techniques involving RNA/DNA hybridization will be used.